“The Intel compiler often produces faster code as the result of
two major optimizations: IPO (Inter Procedural Optimization) and
PGO (Profile Guided Optimization). IPO is a heuristics based
optimization mechanism, while PGO uses several code stages, first
to build code with special modifications that analyse code use, and
then a recompile of the code for better execution based on that
usage. As PGO is based on usage patterns, it can custom design an
optimized kernel for a specific purpose: HPC, DCC, gaming, servers,
etc. Although, PGO is also available in gcc, ICC is generally
regarded as producing a superior result.”